Promiscuous Candida antarctica lipase B-catalyzed synthesis of β-amino esters via aza-Michael addition of amines to acrylates

An efficient protocol for the regioselective aza-Michael addition of amines with acrylates using CaL B as a biocatalyst at 60 °C has been developed. The reaction is applicable to a wide variety of primary and secondary amines with different acrylates to synthesize the corresponding β-amino esters with good yields. An alternative route for the synthesis of higher β-amino esters through the additional transesterification step is also studied and was found effective.